Standardization and Quality Assessment Under the Perspective of Automated Computer-Assisted HEp-2 Immunofluorescence Assay Systems

Abstract

The recent availability of automated computer-assisted diagnosis (CAD) systems for the reading and interpretation of the anti-nuclear antibody (ANA) test performed with the indirect immunofluorescence (IIF) method on HEp-2 cells, has improved the reproducibility of the results and initiated a process of harmonization of this test. Furthermore, CAD systems provide quantitative expression of fluorescence intensity, allowing the introduction of objective quality control procedures to the monitoring of the entire process. The calibration of the reading systems and the automated image interpretation are essential prerequisites for obtaining reproducible and harmonized IIF test results and form the basis for standardization, regardless of the computer algorithms used in the different systems. The use of automated CAD systems, facilitating control procedures, represents a step forward for the quality certification of the laboratory.

Keywords: anti-nuclear antibodies; automation; computer-assisted systems; harmonization; immunofluorescence; standardization.

Figure 1

Complete processing cycle of automated HEp-2 cells assay reading by Aklides system (reproduced from Hiemann R, et al. Challenges of automated screening and differentiation of non-organ specific autoantibodies on HEp-2 cells. Autoimmunity Rev 2009; 9:17-22) (29).

Figure 2

Steps related to quality control and interpretation of the results using the automated CAD procedure for the determination of ANA in indirect immunofluorescence.